Posted: Tue, Nov 13, 2012, 12:56 PM ET (1756 GMT)
Increasing amounts of carbon dioxide in the upper atmosphere may be exacerbating the growing problem of orbital debris, scientists reported this week. Researchers with the Naval Research Laboratory and two universities said that the increasing concentrations of carbon dioxide created by human activities helps cool the upper levels of the atmosphere, the reverse of what carbon dioxide does in the lower atmosphere. That cooling works to contract the thermosphere, reducing the atmospheric drag on debris in low Earth orbit and thus extending it they can remain in orbit. The scientists made those conclusions based on data from an atmospheric chemistry experiment on Canada's SCISAT-1 spacecraft.